Role of the Skin Immune System in Wound Healing

Wound healing is a dynamic and complex process, characterized by the coordinated activities of multiple cell types, each with distinct roles in the stages of hemostasis, inflammation, proliferation, and remodeling. The cells of the immune system not only act as sentinels to monitor the skin and promote homeostasis, but they also play an important role in the process of skin wound repair. Skin-resident and recruited immune cells release cytokines and growth factors that promote the amplification of the inflammatory process. They also work with non-immune cells to remove invading pathogens and debris, as well as guide the regeneration of damaged host tissues. Dysregulation of the immune system at any stage of the process may lead to a prolongation of the inflammatory phase and the development of a pathological condition, such as a chronic wound. The present review aims to summarize the roles of different immune cells, with special emphasis on the different stages of the wound healing process.

Functional TRPA1 Channels Regulate CD56dimCD16+ NK Cell Cytotoxicity against Tumor Cells

Transient receptor potential ankyrin 1 (TRPA1) channels are expressed on the surface of different cell types, including immune cells. However, TRPA1's role in the context of innate and adaptive immune responses has not been fully elucidated so far. In this study, we aimed at investigating the expression and function of TRPA1 channels on NK cells. Among NK cells, TRPA1 was highly expressed by the CD56dimCD16+ subpopulation, but not by CD56brightCD16- cells, as detected by FACS. TRPA1 activation with the potent ligand allyl isothiocyanate (AITC) induces intracellular calcium flux in CD56dimCD16+ cells, which was prevented by the TRPA1 antagonist HC-030031. AITC treatment increased the membrane around NKp44 and strongly decreased CD16 and CD8 expression, while CD158a, CD159a, NKG2d, NKp46 were substantially unaffected. Importantly, AITC increased the granzyme production and CD107 expression and increased NK cell-mediated cytotoxicity towards the K562 cell line and two different melanoma cell lines. In parallel, TRPA1 activation also plays regulatory roles by affecting the survival of NK cells to limit uncontrolled and prolonged NK cell-mediated cytotoxicity. Our results indicate that the activation of TRPA1 is an important regulatory signal for NK cells, and agonists of TRPA1 could be used to strengthen the tumor response of the immune system.

Platelet Derivatives and the Immunomodulation of Wound Healing

Besides their primary role in hemostasis, platelets contain a plethora of immunomodulatory molecules that profoundly affect the entire process of wound repair. Therefore, platelet derivatives, such as platelet-rich plasma or platelet lysate, have been widely employed with promising results in the treatment of chronic wounds. Platelet derivatives provide growth factors, cytokines, and chemokines targeting resident and immigrated cells belonging to the innate and adaptive immune system. The recruitment and activation of neutrophils and macrophages is critical for pathogen clearance in the early phase of wound repair. The inflammatory response begins with the release of cytokines, such as TGF-β, aimed at damping excessive inflammation and promoting the regenerative phase of wound healing. Dysregulation of the immune system during the wound healing process leads to persistent inflammation and delayed healing, which ultimately result in chronic wound. In this review, we summarize the role of the different immune cells involved in wound healing, particularly emphasizing the function of platelet and platelet derivatives in orchestrating the immunological response.

The phosphoinositide-3-kinase (PI3K)-delta inhibitor seletalisib impairs monocyte-derived dendritic cells maturation, APC function, and promotes their migration to CCR7 and CXCR4 ligands

PI3K pathway plays a crucial role in dendritic cells (DCs) functions, as it regulates different cellular processes, such as maturation and cytokines production. However, the specific role of PI3K p110δ isoform in human DCs has not been thoroughly addressed. In this study, we analyze the effects of seletalisib, a potent and specific inhibitor of PI3K p110δ, on phenotype and antigen-presenting functions of monocyte-derived DCs undergone maturation via LPS. Seletalisib treatment reduced membrane HLA-DR as well as CD83 and CD40 costimulatory molecules, whereas CD80 and CD86 expression was only partially affected. Additionally, DCs cultures showed reduced TNF-α, IL-10, and IL-12 and increased IL-23 secretion levels. This resulted in a reduced capacity of DCs to prime allogeneic T cells, with a strong decrease of Th1 differentiation. On the other hand, PI3K p110δ inhibitor seletalisib increased CXCR4 and CCR7 expression and augmented the DCs migration toward CCL19 and CXCL12 ligands. At molecular level, inhibition of PI3K p110δ isoform by seletalisib significantly down-regulated the phosphorylation of AKT and other downstream signaling molecules, such as ribosomal protein S6, 4E-BP1, and NF-κB p65. In contrast, seletalisib did not affect p38 MAP kinase phosphorylation or TLR-associated adapter molecule TIRAP in DCs. Our results indicate that PI3K p110δ can serve as an important regulatory signal for DCs, and selective inhibition of PI3K p110δ isoform by seletalisib could be used for the prevention of exaggerated and harmful immune responses occurring in pathologic conditions, such as autoimmune disorders.

Platelet lysate converts M (IFNγ+LPS) macrophages in CD206+ TGF-β+ arginase+ M2-like macrophages that affect fibroblast activity and T lymphocyte migration

Macrophages, thanks to their extreme plasticity, exert critical roles in wound healing by orchestrating tissue defenses in the early inflammatory phase, and by promoting tissue regeneration and angiogenesis at a later time point. In parallel, platelets release a large number of preformed molecules that could affect immunocyte functions. Platelet-rich plasma and platelet lysate (PL) have been widely used as a therapeutic preside for ulcers, although little is known about the effects of platelet-derived biomolecules on macrophage functions during wound healing. In this study, we analyze the effects of PL on macrophages phenotype and functions. Monocyte-derived macrophages were cultured in the presence of interferon-γ and lipopolysaccharides to induce the M1 polarization and were further exposed to 10% PL. PL treatment reduced CD80, CD86, and PDL-1 and enhanced CD206 and CD200R expression on macrophages analyzed by cytofluorimetry. Additionally, macrophage cultures show reduced TNF-α and CXCL10, while increased arginase protein, PPAR, TGF-β, and VEGF. TGF-β secretion was paralleled by the decrease of NFkB and increase of STAT3, STAT6, and SMAD2 and SMAD4. Supernatants of PL-treated macrophages induced a significant increase of type-I collagen and to a lesser extent of type-III collagen production by fibroblasts. Finally, the supernatant of PL-treated macrophages showed significantly reduced capacity to induce the in vitro migration of T lymphocytes. Our results demonstrate that PL dampens the macrophage secretion of pro-inflammatory cytokines and induces the release of arginase, TGF-β, and VEGF that may affect angiogenesis and tissue regeneration, thus facilitating the wound healing process.

Paradoxical psoriasis induced by TNF-α blockade shows immunological features typical of the early phase of psoriasis development

Immunomodulation with anti‐TNF‐α is highly effective in the treatment of various immune‐mediated inflammatory diseases, including hidradenitis suppurativa (HS). However, this may be responsible for unexpected paradoxical psoriasiform reactions. The pathogenic mechanisms underlying the induction of these events are not clear, even though the involvement of innate immune responses driven by plasmacytoid dendritic cells (pDC) has been described. In addition, the genetic predisposition to psoriasis of patients could be determinant. In this study, we investigated the immunological and genetic profiles of three HS patients without psoriasis who developed paradoxical psoriasiform reactions following anti‐TNF‐α therapy with adalimumab. We found that paradoxical psoriasiform skin reactions show immunological features common to the early phases of psoriasis development, characterized by cellular players of innate immunity, such as pDC, neutrophils, mast cells, macrophages, and monocytes. In addition, IFN‐β and IFN‐α2a, two type I IFNs typical of early psoriasis, were highly expressed in paradoxical skin reactions. Concomitantly, other innate immunity molecules, such as the catheledicin LL37 and lymphotoxin (LT)‐α and LT‐β were overproduced. Interestingly, these innate immunity molecules were abundantly expressed by keratinocytes, in addition to the inflammatory infiltrate. In contrast to classical psoriasis, psoriasiform lesions of HS patients showed a reduced number of IFN‐γ and TNF‐α‐releasing T lymphocytes. On the contrary, IL‐22 immunoreactivity was significantly augmented together with the IL‐36γ staining in leukocytes infiltrating the dermis. Finally, we found that all HS patients with paradoxical reactions carried allelic variants in genes predisposing to psoriasis. Among them, SNPs in ERAP1, NFKBIZ, and TNFAIP genes and in the HLA‐C genomic region were found.

C-Reactive Protein and Procalcitonin as Predictors of Postoperative Inflammatory Complications After Pancreatic Surgery

BACKGROUND

The association between postoperative inflammatory markers and risk of complications after pancreaticoduodenectomy (PD) is controversial. We sought to assess the diagnostic value of perioperative C-reactive protein (CRP) and procalcitonin (PCT) levels in the early identification of patients at risk for complications after PD.

METHODS

In 2014, 84 patients undergoing elective PD were enrolled in a prospective database. Clinicopathological characteristics, CRP and PCT, as well as short-term outcomes, such as complications and pancreatic fistula, were analyzed. Complications and pancreatic fistula were defined based on the Clavien-Dindo classification and the International Study Group on Pancreatic Fistula (ISGPF) classification, respectively. High CRP and PCT were classified using cut-off values based on ROC curve analysis.

RESULTS

The majority (73.8 %) of patients had pancreatic adenocarcinoma. CRP and PCT levels over the first 5 postoperative days (POD) were higher among patients who experienced a complication versus those who did not (p < 0.001). Postoperative CRP and PCT levels were also higher among patients who developed a grade B or C pancreatic fistula (p < 0.05). A CRP concentration >84 mg/l on POD 1 (AUC 0.77) and >127 mg/l on POD 3 (AUC 0.79) was associated with the highest risk of overall complications (OR 6.86 and 9.0, respectively; both p < 0.001). Similarly patients with PCT >0.7 mg/dl on POD 1 (AUC 0.67) were at higher risk of developing a postoperative complication (OR 3.33; p = 0.024). On POD 1, a CRP >92 mg/l (AUC 0.72) and a PCT >0.4 mg/dl (AUC 0.70) were associated with the highest risk of pancreatic fistula (OR 5.63 and 5.62, respectively; both p < 0.05).

CONCLUSIONS

CRP and PCT concentration were associated with an increased risk of developing complications and clinical relevant pancreatic fistula after PD. Use of these biomarkers may help identify those patients at highest risk for perioperative morbidity and help guide postoperative management of patients undergoing PD.

Increased oxidative stress contributes to cardiomyocyte dysfunction and death in patients with Fabry disease cardiomyopathy

Cardiac dysfunction of Fabry disease (FD) has been associated with myofilament damage and cell death as result of α-galactosidase A deficiency and globotriaosylceramide accumulation. We sought to evaluate the role of oxidative stress in FD cardiomyocyte dysfunction. Myocardial tissue from 18 patients with FD was investigated for the expression of inducible nitric oxide synthase (iNOS) and nitrotyrosine by immunohistochemistry. Western blot analysis for nitrotyrosine was also performed. Oxidative damage to DNA was investigated by immunostaining for 8-hydroxydeoxyguanosine (8-OHdG), whereas apoptosis was evaluated by in situ ligation with hairpin probes. iNOS and nitrotyrosine expression was increased in FD hearts compared with hypertrophic cardiomyopathy and normal controls. Remarkably, immunostaining was homogeneously expressed in FD male cardiomyocytes, whereas it was only detected in the affected cardiomyocytes of FD females. Western blot analysis confirmed an increase in FD cardiomyocyte protein nitration compared with controls. 8-OHdG was expressed in 25% of cardiomyocyte nuclei from FD patients, whereas it was absent in controls. The intensity of immunostaining for iNOS/nitrotyrosine correlated with 8-OHdG expression in cardiomyocyte nuclei. Apoptosis of FD cardiomyocytes was 187-fold higher than in controls, and apoptotic nuclei were positive for 8-OHdG. Cardiac dysfunction of FD reflects increased myocardial nitric oxide production with oxidative damage of cardiomyocyte myofilaments and DNA, causing cell dysfunction and death.

Pathology and Function of Conduction Tissue in Fabry Disease Cardiomyopathy

Background—

Cardiac arrhythmias are common in Fabry disease (FD) and may occur in prehypertrophic cardiomyopathy suggesting an early compromise of conduction tissue (CT). Therefore, FD X-linked and CT may be variously involved in male and female patients with FD cardiomyopathy, affecting CT function.

Methods and Results—

Among 74 patients with endomyocardial biopsy diagnosis of FD cardiomyopathy, 13 (6 men; 7 women; mean age, 50.1±13.5 years; maximal wall thickness, 16.7±3.7 mm) had CT included in histological specimens and 6 also at electron microscopy. CT glycolipid infiltration was defined as focal, moderate, extensive, or massive, if involved ≤30%, ≤50%, >50%, or 100% of cells; identified as loosely arranged small myocytes positive to HCN4 immunostaining, supplied by a centrally placed thick-walled arteriole. CT involvement was correlated with age, sex, and α- Gal gene mutation. CT function was evaluated by electrophysiological study and arrhythmias at Holter registration. CT infiltration was focal/moderate in 4 women with no arrhythmias and normal electrophysiological study, extensive in 3 women with atrial or ventricular arrhythmias and short HV interval, and massive in 6 men with atrial fibrillation or ventricular arrhythmias and short HV. Short PR/AH with increased refractoriness was additionally found in 3 patients with extensive/massive CT infiltration. A male patient with the shortest HV presented infra-Hissian block during decremental atrial stimulation. There was no correlation with age, maximal wall thickness, and type of gene mutation.

Conclusions—

CT infiltration in FD cardiomyopathy is constant in men and variable in women because of skewed X-chromosome inactivation; its extensive/massive involvement causes accelerated conduction with prolonged refractoriness and electric instability.

CMR sensitivity varies with clinical presentation and extent of cell necrosis in biopsy-proven acute myocarditis

OBJECTIVES

The aim of this study was to determine whether clinical presentation and type of cell death in acute myocarditis might contribute to cardiac magnetic resonance (CMR) sensitivity.

BACKGROUND

Growing evidence indicates CMR is the reference noninvasive tool for the diagnosis of acute myocarditis. However, factors affecting CMR sensitivity are still unclear.

METHODS

We retrospectively evaluated 57 consecutive patients with a diagnosis of acute myocarditis made on the basis of clinical history (≤3 months) and endomyocardial biopsy evidence of lymphocytic infiltrates (≥14 infiltrating leukocytes/mm(2) at immunohistochemistry) in association with damage of the adjacent myocytes and absence or minimal evidence of myocardial fibrosis. CMR acquisition protocol included T2-weighted (edema), early (hyperemia), and late (fibrosis/necrosis) gadolinium enhancement sequences. Presence of ≥2 CMR criteria denoted myocarditis. Type of cell death was evaluated by using in situ ligation with hairpin probes.

RESULTS

Three clinical myocarditis patterns were recognized: infarct-like (pattern 1, n = 21), cardiomyopathic (pattern 2, n = 21), and arrhythmic (pattern 3, n = 15). Tissue edema was observed in 81% of pattern 1, 28% of pattern 2, and 27% of pattern 3. Early enhancement was evident in 71% of pattern 1, 67% of pattern 2, and 40% of pattern 3. Late gadolinium enhancement was documented in 71% of pattern 1, 57% of pattern 2, and 47% of pattern 3. CMR sensitivity was significantly higher in pattern 1 (80%) compared with pattern 2 (57%) and pattern 3 (40%) (p < 0.05). Cell necrosis was the prevalent mechanism of death in pattern 1 compared with pattern 2 (p < 0.001) and pattern 3 (p < 0.05), whereas apoptosis prevailed in pattern 2 (p < 0.001 vs. pattern 1 and p < 0.05 vs. pattern 3).

CONCLUSIONS

In acute myocarditis, CMR sensitivity is high for infarct-like, low for cardiomyopathic, and very low for arrhythmic clinical presentation; it correlates with the extent of cell necrosis-promoting expansion of interstitial space.

Study of genotypic and phenotypic HIV-1 dynamics of integrase mutations during raltegravir treatment: a refined analysis by ultra-deep 454 pyrosequencing

BACKGROUND

The dynamics of raltegravir-resistant variants and their impact on virologic response in 23 HIV-1-infected patients, who started a salvage raltegravir-containing regimen, were investigated.

METHODS

Integrase population sequencing and Ultra-Deep-454 Pyrosequencing (UDPS) were performed on plasma samples at baseline and at raltegravir failure. All integrase mutations detected at a frequency ≥1% were considered to be reliable for the UDPS analyses. Phylogenetic and phenotypic resistance analyses were also performed.

RESULTS

At baseline, primary resistance mutations were not detected by both population and UDPS genotypic assays; few secondary mutations (T97A-V151I-G163R) were rarely detected and did not show any statistically association either with virologic response at 24-weeks or with the development of resistant variants at failure. At UDPS, not all resistant variants appearing early during treatment evolved as major populations during failure; only specific resistance pathways (Y143R-Q148H/R-N155H) associated with an increased rate of fitness and phenotypic resistance were selected.

CONCLUSIONS

Resistance to raltegravir in integrase strand transfer inhibitor-naive patients remains today a rare event, which might be changed by future extensive use of such drugs. In our study, pathways of resistance at failure were not predicted by baseline mutations, suggesting that evolution plus stochastic selection plays a major role in the appearance of integrase-resistance mutations, whereas fitness and resistance are dominant factors acting for the late selection of resistant quasispecies.

Characterization of drug-resistance mutations in HBV D-genotype chronically infected patients, naïve to antiviral drugs

Presence of drug-resistance mutations in drug-naïve hepatitis B virus (HBV) infected patients can seriously compromise response to antiviral treatment. Therefore, our study was aimed at defining the prevalence of HBV drug-resistance in a population of 140 patients, all infected with HBV-D-genotype (the most common HBV-genotype in Eastern Europe, Mediterranean countries and Middle East) and naïve to antiviral therapy. HBV reverse-transcriptase (RT) region was sequenced and analyzed for 20 mutations, confirmed by in vitro studies as associated with resistance to nucleos(t)ide HBV-RT inhibitors (rtL80I/V-rtI169T-rtV173L-rtL180M-rtA181T/V/S-rtT184A/S/G/C-rtA194T-rtS202C/G/I-rtM204V/I-rtN236T-rtM250V). Amino acid changes at other six RT positions, potentially associated with resistance, were also analyzed (rtV84M-rtV191I-rtV207L-rtV214A-rtQ215S-rtI233V). Overall, only 2/140 (1.4%) patients carried primary drug-resistance mutations [rtA181V (0.7%), and rtA194T (0.7%)], while 3/140 (2.1%) patients harbored the secondary mutations rtV173L (1.4%) and rtL180M (0.7%). Additionally, five polymorphic mutations, with a suggested role in drug resistance, were detected [rtQ215S (12.8%), rtI233V (4.3%), rtV214A (3.6%), rtV191I (0.7%), rtV207L (0.7%)]. Notably, no YMDD mutations, namely rtM204V/I, were found. Taken together, the rate of important drug resistance mutations in naïve HBV D-genotype infected patients is today very low, and suggests the potential full efficacy of new-generation antiviral drugs used in first line therapy. Whether such low rate can be extrapolated to non HBV-D subtypes, requires a detailed investigation to be performed in a different cohort of patients.

Comparative antiviral activity of integrase inhibitors in human monocyte-derived macrophages and lymphocytes

The activity of raltegravir and 4 other integrase inhibitors (MK-2048, L870,810, IN2, and IN5) was investigated in primary human macrophages, PBMC and C8166-lymphocytic T cells, in order to determine their relative potency and efficacy in different cellular systems of HIV infection. Raltegravir showed better protective efficacy in all cell types; MK-2048, L870,810 and IN5 showed a potent anti-HIV-1 activity in macrophages, while in lymphocytes only MK-2048 and L870,810 showed an inhibitory effect comparable to raltegravir. IN2 was a poorly effective anti-HIV-1 compound in all cellular systems. All effective integrase inhibitors exhibited a potent antiviral activity against both X4 and R5 HIV-1 strains. In general, raltegravir, MK-2048, L870,810 and IN5 showed anti HIV activity similar or slightly higher in macrophages compared to PBMC and C8166 T cells: for MK-2048, the EC(50) was 0.4, 0.9, 11.5 nM in macrophages, in PBMCs and T cells, respectively; for L870,810, the EC(50) was 1.5, 14.3, and 10.6 nM, respectively; for IN5 the EC(50) was 0.5, 13.7, and 5.7 nM, respectively.

Secondary integrase resistance mutations found in HIV-1 minority quasispecies in integrase therapy-naive patients have little or no effect on susceptibility to integrase inhibitors

The goal of this study was to explore the presence of integrase strand transfer inhibitor (InSTI) resistance mutations in HIV-1 quasispecies present in InSTI-naïve patients and to evaluate their in vitro effects on phenotypic susceptibility to InSTIs and their replication capacities. The RT-RNase H-IN region was PCR amplified from plasma viral RNA obtained from 49 HIV-1 subtype B-infected patients (21 drug naïve and 28 failing highly active antiretroviral therapy [HAART] not containing InSTIs) and recombined with an HXB2-based backbone with RT and IN deleted. Recombinant viruses were tested against raltegravir and elvitegravir and for replication capacity. Three-hundred forty-four recombinant viruses from 49 patients were successfully analyzed both phenotypically and genotypically. The majority of clones were not phenotypically resistant to InSTIs: 0/344 clones showed raltegravir resistance, and only 3 (0.87%) showed low-level elvitegravir resistance. No primary resistance mutations for raltegravir and elvitegravir were found as major or minor species. The majority of secondary mutations were also absent or rarely present. Secondary mutations, such as T97A and G140S, found rarely and only as minority quasispecies, were present in the elvitegravir-resistant clones. A novel mutation, E92G, although rarely found in minority quasispecies, showed elvitegravir resistance. Preexisting genotypic and phenotypic raltegravir resistance was extremely rare in InSTI-naïve patients and confined to only a restricted minority of secondary variants. Overall, these results, together with others based on population and ultradeep sequencing, suggest that at this point IN genotyping in all patients before raltegravir treatment may not be cost-effective and should not be recommended until evidence of transmitted drug resistance to InSTIs or the clinical relevance of IN minor variants/polymorphisms is determined.

Oxidative stress and HIV infection: target pathways for novel therapies?

Oxidative stress is thought to play an important role in the progression of HIV infection. fact, it has been observed that perturbations in antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Moreover, there is clear evidence that oxidative stress may contribute to several aspects of HIV disease, including viral replication, inflammatory response and decreased immune cell proliferation. For this reason, the exogenous supply of antioxidants, as natural compounds and new-generation antioxidants that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection in the era after HAART therapy has been applied.

Neuroadrenergic and reflex abnormalities in patients with metabolic syndrome

AIMS/HYPOTHESIS

Previous studies have shown that alterations in vascular, metabolic, inflammatory and haemocoagulative functions characterise the metabolic syndrome. Whether this is also the case for sympathetic function is not clear. We therefore aimed to clarify this issue and to determine whether metabolic or reflex mechanisms might be responsible for the possible adrenergic dysfunction.

METHODS

In 43 healthy control subjects (age 48.2+/-1.0 years, mean+/-SEM) and in 48 untreated age-matched subjects with metabolic syndrome (National Cholesterol Education Program's Adult Treatment Panel III Report criteria) we measured, along with anthropometric and metabolic variables, blood pressure (Finapres), heart rate (ECG) and efferent postganglionic muscle sympathetic nerve activity (microneurography) at rest and during baroreceptor manipulation (vasoactive drug infusion technique).

RESULTS

Compared with control subjects, subjects with metabolic syndrome had higher BMI, waist circumference, blood pressure, cholesterol, triglycerides, insulin and homeostasis model assessment (HOMA) index values but lower HDL cholesterol values. Sympathetic nerve traffic was significantly greater in subjects with metabolic syndrome than in control subjects (61.1+/-2.6 vs 43.8+/-2.8 bursts/100 heartbeats, p<0.01), the presence of sympathetic activation also being detectable when the metabolic syndrome did not include hypertension as a component. Muscle sympathetic nerve traffic correlated directly and significantly with waist circumference (r=0.46, p<0.001) and HOMA index (r=0.49, p<0.001) and was inversely related to baroreflex sensitivity (r=-0.44, p<0.001), which was impaired in the metabolic syndrome.

CONCLUSIONS/INTERPRETATION

These data provide evidence that the metabolic syndrome is characterised by sympathetic activation and that this abnormality (1) is also detectable when blood pressure is normal and (2) depends on insulin resistance as well as on reflex alterations.

Sympathetic and reflex abnormalities in heart failure secondary to ischaemic or idiopathic dilated cardiomyopathy

Congestive heart failure (CHF) is characterized by a sympathetic activation and a baroreflex impairment whose degree is directly related to the clinical severity of the disease. However, whether these abnormalities vary according to the ischaemic or idiopathic dilated nature of the CHF state has not been conclusively documented. In patients with a clinically stable, chronic CHF state in New York Heart Association functional class II and III, due either to ischaemic heart disease (IHD; n=22, age 60.3+/-2.4 years, means+/-S.E.M.) or to idiopathic dilated cardiomyopathy (IDC; n=20, age 58.9+/-2.8 years), and in 30 age-matched controls, we measured arterial blood pressure (using a Finapres device), heart rate (by electrocardiogram) and postganglionic muscle sympathetic nerve traffic (by microneurography) at rest and during baroreceptor manipulation induced by the vasoactive drug-infusion technique. Blood pressure values were not significantly different in CHF patients and controls. Compared with controls, heart rate was similarly increased and left ventricular ejection fraction (by echocardiography) similarly reduced in CHF patients with IHD or IDC. Muscle sympathetic nerve traffic was significantly greater in CHF patients than in controls, and did not differ between patients with IHD or IDC (67.3+/-4.2 and 67.8+/-3.8 bursts/100 heart beats respectively). This was also the case for the degree of baroreflex impairment. These data show that CHF states due to IHD or to IDC are characterized by a similar degree of peripheral sympathetic activation and by a similar impairment of the baroreflex function. Thus the neuroadrenergic and reflex abnormalities characterizing CHF are independent of its aetiology.

[Diltiazem and modulation of platelet aggregation]

The calcium antagonists including Diltiazem have been proved to inhibit platelet aggregation caused by ADP. In order to demonstrate the anti-aggregant properties of Diltiazem, a study was conducted on the aggregation curves in blood samples from 20 healthy subjects before and after a week's treatment with 240 mg oral Diltiazem per diem. The experiment confirmed the anti-aggregant properties of Diltiazem which is therefore useful in the treatment of cardiovascular disease given its capacity to dilate the coronary arteries and inhibit platelet aggregation.